AT27C040-15JC Equivalent & Substitute Parts

Part Overview

The AT27C040-15JC is a 4Mbit EPROM (Erasable Programmable Read-Only Memory) manufactured by Microchip Technology in a 32-PLCC surface mount package. This part operates with a 150 ns access time and is classified as obsolete. Due to its obsolete status and limited availability in modern supply chains, identifying functionally equivalent substitute parts is essential for system redesign, legacy system maintenance, and production continuity.

Substiute Parts

AT27C040-15JC

Microchip TechnologyIn Stock: 2110AT27C040-15JC Datasheet

Current PartRFQ

AT27C040-90JU

Microchip TechnologyIn Stock: 1363AT27C040-90JU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT27C040-15JC is determined by the following critical parameters:

• Memory Capacity & Organization: Must be 4Mbit with 512K x 8 organization to maintain pin-for-pin compatibility and functional equivalence
• Memory Interface: Must be parallel interface to match the existing circuit design
• Package Type: Must be 32-PLCC with identical physical dimensions (13.97x11.43 mm) for PCB compatibility
• Voltage Supply Range: Must operate within 4.5V ~ 5.5V to ensure compatibility with existing power distribution
• Access Time: The AT27C040-15JC operates at 150 ns; faster variants (90 ns) are functionally compatible as they meet or exceed performance requirements

The AT27C040-90JU from Microchip Technology qualifies as a direct substitute based on these parameters. It maintains identical memory capacity, organization, interface type, and package specifications while offering improved access time performance.

Parameter Comparison

Engineering Selection Recommendations

The AT27C040-90JU is the qualified substitute for the AT27C040-15JC based on the following factors:

• Functional Equivalence: Identical memory capacity, organization, and parallel interface ensure direct functional replacement without circuit modification
• Pin Compatibility: Identical 32-PLCC package with matching physical dimensions enables direct PCB substitution
• Performance Enhancement: The 90 ns access time exceeds the original 150 ns specification, providing improved system performance
• Product Availability: Active product status ensures continued availability and supply chain reliability compared to the obsolete original part
• Compliance Improvement: ROHS3 compliance of the substitute addresses modern regulatory requirements, whereas the original part is RoHS non-compliant
• Temperature Range Expansion: Extended operating temperature range (-40°C ~ 85°C) provides greater operational flexibility than the original specification (0°C ~ 70°C)

Frequently Asked Questions (FAQ)

Q: Can the AT27C040-90JU be used as a direct replacement for the AT27C040-15JC?

A: Yes. Both parts share identical memory capacity (4Mbit), organization (512K x 8), parallel interface, and 32-PLCC package specifications. The substitute operates at 90 ns access time, which is faster than the original 150 ns specification, ensuring functional compatibility.

Q: What are the key differences between these parts?

A: The primary differences are access time (90 ns vs. 150 ns), operating temperature range (-40°C ~ 85°C vs. 0°C ~ 70°C), product status (Active vs. Obsolete), and compliance certifications (ROHS3 Compliant vs. RoHS non-compliant).

Q: Will the faster access time of the AT27C040-90JU cause compatibility issues?

A: No. Faster access time is a performance enhancement that maintains backward compatibility. Systems designed for 150 ns operation will function correctly with 90 ns components.

Q: Are there any PCB layout considerations when substituting these parts?

A: No. Both parts use identical 32-PLCC packaging with matching physical dimensions (13.97x11.43 mm), requiring no PCB modifications.

Q: What is the voltage supply requirement for both parts?

A: Both the AT27C040-15JC and AT27C040-90JU operate within the 4.5V ~ 5.5V supply range, ensuring compatibility with existing power distribution systems.

Q: Does the substitute part require any firmware or software changes?

A: No. The substitute maintains identical memory organization and parallel interface specifications, requiring no changes to firmware, software, or system configuration.